CVE-2026-120971

A flaw was found in RESTEasy's default exception mapper. When an unhandled exception other than a WebApplicationException is not handled by an application exception mapper, RESTEasy returns the exception's localized message in the HTTP 500 response body. A remote unauthenticated attacker who can trigger such an exception may obtain information contained in that message. The behavior was reproduced with RESTEasy 7.0.2.Final.